Question

..ll Fido LTE @ 95% 7:44 AM edge.edx.org A friend of yours runs a trucking company that has a few refrigerated trucks. He has recently been offered a contract to ship food from Mexico to Canada. However he is worried about whether the refrigeration will be good enough to keep food cold in the summer in Mexico, where the temperature often gets up to 40°C. Because he knows you have taken physics he asks you to help him figure it out. You look over the truck and make some measurements. The area of the refrigerated walls is 172.5 m². The compartment has foam insulation about 10 cm thick and a thermal conductivity of 0.024 W/(m K). Your friend tells you that the internal volume is 83 cubic meters, and the inside temperature of the refrigerated compartment is maintained at 3 C. The refrigerated compartment has a refrigeration system that tries to maintain a constant temperature inside it, and will only turn on when the interior temperature is too high. The refrigeration system is rated at 4000 W (this is its total rate of energy consumption during operation) and has an efficiency of about 50%.

Answer 1

system to keep the for the food refrigeration cold Power supplied - Power lost through conduction . Powes moquined - KAAT 42 Kathormal conductivity As area of cross section. At-s temperaturom difference And thickness a power requined n ot Per Por 0-0QHX 172.5 x (40-3) 10x102 - 1531.8 W Griven power rating = 4000 W efficieny - soy & Power supplied - 50 40000 100 8000 W Since Power supplied > Power requined & The cool. system can keep the food